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Author Topic: PK Sharpener Question  (Read 33759 times)

Dave (Isle of Skye)

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Re: PK Sharpener Question
« Reply #40 on: June 24, 2013, 05:06:02 pm »

I am not inside Guy's inner circle either, never have been and don’t intend to join, but having now watched the video link myself and which I found as equally entertaining as it was annoying, I think it is not that difficult to look past Guy’s hyperbole and work out the steps that Guy has put into his sharpening action, to achieve what he is suggesting is a more adaptive sharpening method, and which is probably based on an old method of sharpening via the channels and luminosity selections, but with a few updates and tweaks added - I imagine.

But for the sake of not throwing the baby out with the bathwater and to play a little bit of the devil’s advocate, I do think that Guy points out quite a few general truths about the standardised approach to sharpening, that most of us have relaxed into and now use without thought:

1 – Sharpening an image optically, by evaluations based on the screen, is not always the best method to sharpen an image, due to screen resolution and clarity of detail etc, and neither is it necessarily representative of the sharpening or acutance being applied to the actual data within the image.

2 – Sharpening an image optically and without regard to the output device, is also not the best way to achieve optimum output sharpening.

3 – Applying a ‘standard’ level of sharpening across all areas of the image, in the shadows, quarter tones, mid tones, three quarter tones and highlights equally, is again not the most effective way to produce the best sharpening of all areas within an image.

4 – Sharpening an image with wang bars (as Guy calls them), until the data in the most effected areas becomes too crunchy or haloed and then pulling back the wang bars to a level of acceptability as dictated by the worst affected areas, and without regards to the other areas that may require more sharpening, is also not the most effective way to sharpen an image.

5 – Adding more wang bars to a sharpening tool, can add unnecessary and misunderstood extra choices to the average user.

6 – Standard sharpening tools used in a standard way, are not sufficiently intuitive to allow the user to apply sharpening in a graduated or selective manner, based on the areas within each image that require more or less sharpening.

7 - Applying sharpening to each and every image through individual experimentation, is bound to slow down your workflow and provide you with inconsistent results.

8 – Basing the sharpening on the actual pixel data (tonality, colour and levels of luminosity) within each individual image, should provide a better method of sharpening, especially if it can be achieved and applied easily and automatically, yet still creating a flexible and graduated result, based solely on the information within each and every image.

So even though Guy comes down hard on most if not all modern sharpening tools and methods (high pass and ACR etc), he does put forward a few arguments that cannot be easily or at least entirely dismissed.

However Guy’s hyperbolic delivery, sprinkled with snippets of truth hidden behind a well developed hard edged sales patter, that plays heavily towards his strong points while hiding any weaknesses, and that warns us – whatever you do and whatever anyone else could do or tell you to do, is always going to be so much less than what you could ever hope to achieve if you pay for Guy’s help, because without his help, you are bound to be wrong, as only he has the key to the one true answer, is bound to put a lot of people off him and generate cries of ‘snake oil’ etc, but to dismiss everything he says outright just because he has decided to deliver his ‘solution’ in a way that seeks to denigrate every other method and tool, might be as I said earlier, an act of throwing out the baby with the bathwater.

So even though I think that overall, Guy is probably more wrong than he is right, there are still some areas where it does seem as though he is right, or at least very close to it.

Dave
« Last Edit: June 24, 2013, 05:09:33 pm by Dave (Isle of Skye) »
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Schewe

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Re: PK Sharpener Question
« Reply #41 on: June 24, 2013, 06:08:52 pm »

So even though Guy comes down hard on most if not all modern sharpening tools and methods (high pass and ACR etc), he does put forward a few arguments that cannot be easily or at least entirely dismissed.

Ever hear of Bruce Fraser's Thoughts on a Sharpening Workflow? Written about the time we finished PhotoKit Sharpener...in it Bruce advocates a capture, creative and output sharpening 3 pass approach. Which is exactly what Camera Raw and Lightroom were designed for. It addresses most if not all of Guys points (and predates them since Bruce 1st advocated multi-pass sharpening in his Real World Photoshop 3 book in 1996).

You can already apply global sharpening in ACR/LR and modulate the sharpening in the local controls...you can paint out sharpening or paint it in stronger locally. Yes, it requires some hand work...a few seconds to click on the Adjustment Brush and a few seconds to paint some strokes...Capture sharpening WAS designed to be evaluated on screen at 100%.

As far as output sharpening, Lightroom (and ACR) have that built in. The logic and routines were licensed by Adobe from PG for ACR/LR and no, you CAN'T properly sharpen for output sharpening on screen...that's why LR doesn't even let you see the results. That's on purpose...

The only point that Guy is somewhat right about is that the 5 sliders for sharpening (I count luminance noise reduction the 5th slider) isn't intuitive and needs to be learned. I've tried to teach people what the adjustments do and how to use them...Guy doesn't even bother–largely because I suspect he doesn't really understand them.

Can you do more exotic sharpening in Photoshop using a variety of masks and selections? You bet...but creating an edge mask is about a 15 step operation in Photoshop where in ACR/LR it's a wang bar fully adjustable between zero and 100. Hum, can you duplicate it in Photoshop? You bet...is it better in Photoshop? That's debatable. Are there 3rd party tools that extend even further than Photoshop? You bet...some have been mentioned here in this thread (but not mentioned by Guy of course).

So, yes, it takes some time and effort to learn how to use ACR/LR sharpening. Course, Guy isn't much of a help there. He just denigrates the tools and wants to sell you actions (which ironically depend on some of the same tools he denigrates).

Come on Dave, you aren't really drinking Guy's Kool-Aid are ya?
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bwana

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Re: PK Sharpener Question
« Reply #42 on: June 24, 2013, 09:50:53 pm »



You can already apply global sharpening in ACR/LR and modulate the sharpening in the local controls...you can paint out sharpening or paint it in stronger locally. ...

The only point that Guy is somewhat right about is that the 5 sliders for sharpening (I count luminance noise reduction the 5th slider) isn't intuitive and needs to be learned. I've tried to teach people what the adjustments do and how to use them...

So, yes, it takes some time and effort to learn how to use ACR/LR sharpening. ...

I sometimes have trouble getting the creative sharpening I want to be what is printed. I set my view to 30%-50% which on my 100 dpi monitor should mimic 300-200 dpi printed output. And white halos are a pain as well...way back in the beginning I thought they were a little....cool. ??? but now they are splinters that i have to pluck out using "painted in sharpening" in only the areas of the photo that I want to draw the viewer to..

I do not have as much experience as others do playing with the cumulative effect of those sliders. As the algorithms behind them undoubtedly changed since Bruce wrote his books, I would welcome a comparative treatment of the same photograph using these two different workflows (PS based as illustrated by Guy, LR based as advocated by Schewe). I would even pay to watch 'workflow olympics' where great post-process artists are given the same raw image and 10 minutes to make it 'great' in the eyes of an anonymous panel of judges (us). I think Guy's tutorials are good because they emphasize the graphic qualities he is trying to portray and bring out in a photo. There is discussion about the form of an image, the tonal gradation, the color cast, the shadow noise. Although he does come down hard on his wang bars, I think it's not the Adobe tech that he is slamming, but the fact that they are so easy to misuse. As I am sure I do, often by accident. Still, if there is a thoughtful, simple webcast on the use of LR to achieve the kind of purposeful enhancement of an image, please point me to it.
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Schewe

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Re: PK Sharpener Question
« Reply #43 on: June 24, 2013, 11:38:31 pm »

I sometimes have trouble getting the creative sharpening I want to be what is printed. I set my view to 30%-50% which on my 100 dpi monitor should mimic 300-200 dpi printed output.

Uh, you can't evaluate the final sharpening on a computer display. Even if you zoom out to 50-25%, you are looking at a higher rez image at 1/3 to 1.4 the resolution if your display is 100 ppi. All you can do is do the proper capture sharpening add creative sharpening and the final output sharpening should not break the image.

Just so you know, I would have absolutely ZERO interest in engaging in a sharpening competition...I've written books and done video tutorials and I post here on LuLa and the Adobe forums. Sorry, but have neither the time nor inclination to engage in that sort of circus...and to he brutally honest, I've now seen two essentially worthless videos by Guy...I won't be watching another one.

Quote
Although he does come down hard on his wang bars, I think it's not the Adobe tech that he is slamming, but the fact that they are so easy to misuse.

Did you see the same videos I did? In essence, he said ACR and LR are crap. He slams Adobe, he slams the engineers, he slams everything including Photoshop. Oh, he talks pretty glowingly about Aperture...I wonder why?
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texshooter

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Re: PK Sharpener Question
« Reply #44 on: June 25, 2013, 01:40:46 am »


Just so you know, I would have absolutely ZERO interest in engaging in a sharpening competition...

You mean even with a man who Photography Monthly says:

He is a legend in the world of digital imaging, workflow and manipulation.
His opinions set the agenda for manufacturers worldwide
As a leading authority, he is regularly retained by clients such as Adobe, Apple and Wacom
At the age of 19 he was the sole operator of the earliest digital scanner.
What he doesn't know about Photoshop is not worth knowing.

And you say you never heard of the man? Do you live under a rock?  ;)
« Last Edit: June 25, 2013, 02:01:45 am by texshooter »
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Schewe

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Re: PK Sharpener Question
« Reply #45 on: June 25, 2013, 01:54:53 am »

You mean even with a man who Photography Monthly says:

What's Photography Monthly? Sorry, never heard of it...maybe I do live under a rock...(although I tend not to read photo magazines that features dogs on the cover–silly me).

Like I said, Guy is a legend in his own mind...
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Bart_van_der_Wolf

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Re: PK Sharpener Question
« Reply #46 on: June 25, 2013, 04:59:05 am »

Uh, you can't evaluate the final sharpening on a computer display. Even if you zoom out to 50-25%, you are looking at a higher rez image at 1/3 to 1.4 the resolution if your display is 100 ppi. All you can do is do the proper capture sharpening add creative sharpening and the final output sharpening should not break the image.

Hi Jeff,

While that's essentially true, it may escape some readers why that is so. The reasons are quite simple and, more importantly, one can learn through experience how to deal with them.

Proper Capture sharpening is something that has not been understood well by many, for a long time, and some still don't. All it's supposed to do is recover from (as much as feasible) the sharpness (resolution and contrast) losses incurred during the Capture process. Some are still using yesteryear's tools (because nothing better was available back then) with some added features to hide the shortcomings.

What many do not realize is that the Capture process losses can be accurately predicted and quantified because they are predictable physical processes. When we know what caused them (optics, diffraction, sampling), we can use modern techniques (like Deconvolution) to recover from them to a large degree. BTW, the optics not only hurt the original signal's resolution due to residual aberrations, but are also a major cause of contrast loss due to veiling glare (which is not really being addressed by the ancient tools).

Modern Capture sharpening tools are quite outdated in their design, and they look very much like USM sharpening tools with some extras for artifact suppression.

UnSharp Masking (USM) based tools are just that, yesteryear's tools. They mimic a process that was used with analog film, and turned it into a digital tool that produces the same kind of artifacts as there were in film, and then uses edge masking techniques to cover up most of those artifacts. That's ancient, and it's also what Guy Gowan seems to use, although he seems to focus more on the final output than on real Capture sharpening.

The image as displayed on screen, can help to look in detail whether the adjustments do or don't create artifacts, but it cannot give a good impression of the real effect on final output, mainly because the display resolution is too low. Of course, through experience one can develop a feeling of how things will ultimately work out in output. The experience part is often not mentioned by those who slam the usefulness of judging on display sharpening adjustments.

Creative sharpening is a term that inaccurately describes all of the actual processes at this stage, because from it's origin it's partly based on the same ancient USM sharpening techniques. Of course it usually has relatively little to do with sharpening, but more with local contrast adjustments, e.g. Clarity.

Modern implementations of this Creative stage of image manipulation can, thanks to modern Digital Signal Processing (DSP) techniques (e.g. Wavelets and other frequency domain based adjustments), indeed address the manipulation (amplification or reduction) of specific spatial frequency bands in specific areas of the image. But most of the Creative influence on the overall look of an image comes from Local Contrast adjustments, not real sharpening but the impression of sharpness caused by contrast. Contrast suggests subject matter surface detail will be brought out by harsh lighting.

To get some idea about how the result will look in final output, one can very roughly approximate it by zooming out to a true output size on screen representation. The finer detail adjustments cannot be accurately judged on screen though, because the display resolution is too low, and the quick down-sampling not accurate enough. Through experience though, one can develop a feeling for how things will work out in the final output.

Output sharpening is usually also hard to exactly jugde on display, again, because the display resolution is too low, and because a light emitting output device has a different characteristic compared to reflective printed output, and viewing conditions can have quite a different effect on both. Of course when output is generated for screen display, e.g. Web Publishing, it becomes easier to judge the final result for a given display type (although there are a lot of different display qualities available for which one can optimize).

Again, experience plays a large role here in judging how the on screen adjustments will translate to the actual output medium. So while the on screen displayed image is not an accurate preview, one can learn how to translate that preview to how things will actually look, and experience takes time to develop.

Cheers,
Bart
« Last Edit: June 25, 2013, 05:05:56 am by BartvanderWolf »
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PhotoEcosse

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Re: PK Sharpener Question
« Reply #47 on: June 25, 2013, 05:04:14 am »

What's Photography Monthly? Sorry, never heard of it...maybe I do live under a rock...(although I tend not to read photo magazines that features dogs on the cover–silly me).



Photography Monthly is one of the many photographic monthlies. This month (July) has a bee on the cover. Prettier than a dog.

I think there is a problem with photographic magazines nowadays - far too many of them and a general dropping in standard. It seems that every major publishing house has to have at least three photographic titles. Photography Monthly is one of Archant's.

I remember the halcyon days of the 1950s when there were only two popular photographic magazines in UK - Amateur Photographer (weekly) and Practical Photography (monthly).

But, imho, the main problem is the standard of the journalism. It would not surprise me in the least if the quotations cited above were supplied by the subject himself, rather than being properly researched.

This new-fangled internet thing has a lot to answer for.
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digitaldog

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Re: PK Sharpener Question
« Reply #48 on: June 25, 2013, 10:03:46 am »

And you say you never heard of the man? Do you live under a rock?  ;)

I must be under a rock too, never heard of the that guy Guy until this post. Or that magazine (although while I haven’t seen it, I like dogs on covers and on the bed <g>).

I've been 'involved' with imaging since Photoshop 1.0.7 shipped in 1990, how could I have missed Guy? I recall Kai from under that rock a long time ago.
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Garnick

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Re: PK Sharpener Question
« Reply #49 on: June 25, 2013, 10:33:46 am »

I must be under a rock too, never heard of the that guy Guy until this post. Or that magazine (although while I haven’t seen it, I like dogs on covers and on the bed <g>).

I've been 'involved' with imaging since Photoshop 1.0.7 shipped in 1990, how could I have missed Guy? I recall Kai from under that rock a long time ago.

Oh come on Andrew...you haven't heard of the "GUY"?  12am every night on GGN(the Guy Gowan Network).  Ya, a well known talk show.  Of course it's "GUY" who does all of the talking.  Catch it sometime, it's a great replacement for the Nighty Night pill.  Only problem is, ummmm...it sucks.
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Dave (Isle of Skye)

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Re: PK Sharpener Question
« Reply #50 on: June 25, 2013, 01:24:04 pm »

Come on Dave, you aren't really drinking Guy's Kool-Aid are ya?

No Jeff, not at all - BTW we don't have Kool-Aid in the UK, or any understanding of the term 'drinking Kool-Aid', although from your use of it, I think I get your drift  :D

But no, I am not swallowing what Guy has said in the slightest, or his overly persuasive sales technique that seeks to hide snippets of truth below a veil of mystery and yet to be revealed magic. His solution may not be worth anything at all, but if nothing else, he has given me enough food for thought to now drag myself out of the idleness that I had fallen into, of not being more attentive to exactly what I am doing when sharpening an image.

Dave
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Rajan Parrikar

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Re: PK Sharpener Question
« Reply #51 on: June 25, 2013, 01:54:21 pm »


Output sharpening is usually also hard to exactly jugde on display, again, because the display resolution is too low, and because a light emitting output device has a different characteristic compared to reflective printed output, and viewing conditions can have quite a different effect on both. Of course when output is generated for screen display, e.g. Web Publishing, it becomes easier to judge the final result for a given display type (although there are a lot of different display qualities available for which one can optimize).

Again, experience plays a large role here in judging how the on screen adjustments will translate to the actual output medium. So while the on screen displayed image is not an accurate preview, one can learn how to translate that preview to how things will actually look, and experience takes time to develop.

Cheers,
Bart

Bart,

Somewhat tangential but, I think, relevant - the era where photos will mostly be exhibited on hi-res digital panels is not far off.  While a paper print is held up (by some) as the gold standard today, once the price of large hi-res panels drops, the game will change.
« Last Edit: June 25, 2013, 01:58:25 pm by Rajan Parrikar »
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Bart_van_der_Wolf

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Re: PK Sharpener Question
« Reply #52 on: June 25, 2013, 02:36:39 pm »

Bart,

Somewhat tangential but, I think, relevant - the era where photos will mostly be exhibited on hi-res digital panels is not far off.  While a paper print is held up (by some) as the gold standard today, once the price of large hi-res panels drops, the game will change.

Hi Rajan,

Indeed, and I suppose that already more images are viewed on (low) resolution displays than there are printed, certainly large format. So it should be relatively doable to judge the sharpening for Low or High resolution displays on a reasonably calibrated display (which would allow at least some idea of how it could look on all those mediocre displays). A bit of experience goes a long way for when high resolution displays become mainstream.

Cheers,
Bart
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digitaldog

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Re: PK Sharpener Question
« Reply #53 on: June 25, 2013, 03:27:09 pm »

I assume you haven't seen the video I was referring to from the "Guy".

Watched the first 16 minutes and had to stop for a reality break. I didn't learn anything other than his opinions about how great film and his Crosfield scans were, how everything else is subpar. I'm OK with a tutorial having some opinions mixed in with some actual teaching. But literally, there was no information disseminated in all that time. I suspect even someone totally new to the subject would have gotten nothing out of that first 25% of what is going to end up being a very long video. I'll continue to watch it as I'm sure at some point, something has to be discussed on the subject that is information based.

I'm not a fan of fast food quickie tutorials but at least the author's cut to the chase and if there are opinions, it's a 10%/90% ratio. What I saw of Guy's video in 15 minutes was more like 95% opinion and 5% possible information and I think I'm being generous! When Jeff says an hour of his life wasted, I get the idea and thus stopped quarter way through. But I'll give the guy another 15 minutes.
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bjanes

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Re: PK Sharpener Question
« Reply #54 on: June 26, 2013, 05:36:38 pm »

Note that in Camera Raw, the clipping calculations are done in 8 bit based on the output color space set in Workflow Options. Also note there are 3 potential clipping indicators; holding down the option/alt keys when adjusting certain sliders, the on screen red for highlights and blue for shadows and the flashing triangle indicators on the histogram. Of the three perhaps the most accurate are the option/alt when moving a slider and the red/blue on screen indicator.

So, evaluating the differences between PV 2010 and 2012 in terms of clipping indicators being in 8 bit, it wouldn't surprise me that PV 2012 can (and does) get at more highlight texture detail that is not really clipped while PV 2010 shows the data as clipped.

When talking about "recovery", I think a lot of people get confused between recovery vs compression. PV 2012 does a lot of extreme highlight compression to mitigate clipping. Some people don't like that and you can work around that by using curves. When I think of recovery I think of the old Recovery algorithm in PV 2010. PV 2012 is NOT doing that sort of recovery...and PV 2012 doesn't suffer from the same color contamination that PV 2010 suffered from.

PV 2012 was originally designed for use in floating point HDR images...(see the Local Laplacian Filters article). It was adapted to work on non-HDR image in ACR/LR by the engineers and believe me, when I read the SIGGRAPH paper, my eyes rolled back in my head. I don't understand that stuff and never will.

But, I do know how to tell really smart people from not so smart people. I know Thomas and Eric pretty well and I've met Sylvain Paris (one of the authors of the paper) and they are really, really smart. I don't like the way Guy accuses Adobe of arrogance and denigrates the work of these guys...neither Thomas nor Eric are arrogant. OK, Mark Hamburg (the guy that started Lightroom and the second engineer to work on Photoshop) is a bit arrogant...but the engineers do this stuff to get the absolute best they can out of raw captures. They are not predisposed to back off on the raw processing and simply fix it in Photoshop.

I don't want to get involved in the discussion of Guy's sharpening workflow other than to state that he does not seem to know LR or ACR and his criticism of Adobe, Thomas, and Eric is misguided. However, he does point out valid differences in clipping indicators between PV2010 and PV2012. I will use LR5 to demonstrate these differences with a shot of a Stouffer wedge in which the green channels are blown in the raw file as shown by the Rawdigger histogram and overexposure indicator. Exposure was at 5000K on a lightbox. WB set to auto gave neutral results and a red multiplier of 1.973 and a blue multiplier of 1.555 so that the red and blue channels would also be clipped with white balance.

Here is the histogram of the file as shown by Rawdigger.


And the Rawdigger clipping indicator.


The baseline offset for the D800e is +0.35 EV, so a negative exposure of -0.35 must be used with LR/ACR. Using LR with PV2010 and a linear tone curve shows the clipped channels.

Clipping indicator with PV2010 shows clipping similar to that shown with Rawdigger:


Alt exposure slider method with PV2010:


The PV2012 clipping indicator shows no clipping.


The Alt Exposure method with PV2012 also shows no clipping.


The conclusion is that PV2010 does give a more accurate indication of clipping.

Bill
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Re: PK Sharpener Question
« Reply #55 on: June 26, 2013, 05:46:32 pm »

I'm a bit confused Bill.

RD shows clipping, I get that. But then PV2012 shows none so is this clipping 'eliminated' by rebuilding that channel from the other two (an old 'trick' that was done in the past but perhaps differently with the new process)?
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bjanes

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Re: PK Sharpener Question
« Reply #56 on: June 26, 2013, 06:35:44 pm »

I'm a bit confused Bill.

RD shows clipping, I get that. But then PV2012 shows none so is this clipping 'eliminated' by rebuilding that channel from the other two (an old 'trick' that was done in the past but perhaps differently with the new process)?

Andrew,

That is my take on the findings: PV2012 has applied an adaptive correction of the highlight clipping. The maximal pixel value with PV2012 is 253 but the upper tones are compressed. With PV2010 the first two steps are clipped to 255 and the third shows a color shift as shown. The PV2010 rendering is on the top.

Bill
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Re: PK Sharpener Question
« Reply #57 on: June 26, 2013, 06:39:37 pm »

That is my take on the findings: PV2012 has applied an adaptive correction of the highlight clipping. The maximal pixel value with PV2012 is 253 but the upper tones are compressed. With PV2010 the first two steps are clipped to 255 and the third shows a color shift as shown. The PV2010 rendering is on the top.

OK so it's rebuilding data in some respect and if so, it's accurate (the net results are, no clipping).

On the other hand, it's not accurate in terms of the actual data prior to rebuilding depending on how you want to look at it. IOW, PV2013 shows no clipping because it's going to produce no clipping. Sound about right?
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bjanes

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Re: PK Sharpener Question
« Reply #58 on: June 26, 2013, 06:49:36 pm »

OK so it's rebuilding data in some respect and if so, it's accurate (the net results are, no clipping).

On the other hand, it's not accurate in terms of the actual data prior to rebuilding depending on how you want to look at it. IOW, PV2013 shows no clipping because it's going to produce no clipping. Sound about right?

Andrew,

Does LR5 use PV2012 or PV2013? The current process is identified as PV2012 in the LR display. In any event, the histogram shows the values in the rendered file, but does not indicate clipping in the raw file. This could cause problems when one is judging ETTR exposures.

Bill
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Re: PK Sharpener Question
« Reply #59 on: June 26, 2013, 06:55:20 pm »

Does LR5 use PV2012 or PV2013? The current process is identified as PV2012 in the LR display.

Sorry, typo on my part. There is no PV2013 (I'm referring to PV2012).
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